This happened to me recently and I found it unsettling. What seems to be the consensus from neighborhood blogs, etc., is that it isn't a scam per se, but the execution is extremely shady. They came to my house and asked if I'd heard of cancer and if I was scared of it (lol) and then said they needed to see my energy bill, which is when I said I didn't have it and couldn't help them because it seems pretty fair to not show strangers on your porch your financials. I think the end game is a sales pitch to get you to switch to a legitimate clean energy carrier, but the method is scammy and also financially risky.